Moonshot AI launches Kimi chatbot with 128K context

Moonshot AI, a Beijing startup founded only months earlier by researchers with ties to Tsinghua University, launched Kimi Chat, an assistant it said could process up to 200,000 Chinese characters — reported in English-language coverage as a 128,000-token context window — in a single lossless pass. The company said this made it the first consumer-facing AI product on the market able to handle context of that length, letting users paste in entire academic papers, contracts or codebases rather than working around a chatbot’s short memory.

Long-context handling was a comparatively underserved capability among large chatbots at the time: most consumer products still limited users to a few thousand tokens of conversation history, forcing them to summarise or split long documents before a model could use them. Moonshot AI marketed Kimi specifically around use cases that depended on ingesting whole documents at once — legal analysis, technical documentation and academic translation among them — rather than competing head-on with general chatbot leaders on breadth of ability.

Kimi opened to open beta testing the day after its announcement and was made available to the general public in mid-November 2023. The launch established Moonshot AI, later valued among China’s best-funded AI startups with backing that included Alibaba, as one of several Chinese labs — alongside Baidu, Alibaba, Zhipu and others — racing to ship consumer large-language-model products through the second half of 2023, with long-context handling as Moonshot’s initial point of differentiation.